1. Technical Field
The present invention generally relates to devices that separate solids from air and, more particularly, to a device that separates scrap from a transport air flow. Specifically, the invention relates to an air material separator or receiver that has compact dimensions and a low overall weight that allow it to be positioned inside a building instead of on the roof as in the prior art.
2. Background Information
Various systems use a pneumatic conveying system to remove scrap from a processing area and to deliver the scrap to a waste container. In the context of this patent application, the terms scrap, trim, broke, edge trim, waste, and web shall be used interchangeably to reference items that are being transported by an air stream and then separated from the air stream. Each of these pneumatic conveying scrap systems uses an air material separator to separate the scrap from the air stream. The scrap may be paper, plastic, film, finished products, cellulose casings, meat packing casings, packing materials, fiberglass, tissue, fabric, or metal foils. The scrap may be supplied in individual pieces or in continuous lengths.
Prior art air material separators have been located outside or on the roof of a building because their heights typically prevent the device from being located inside the building. The roof location was acceptable in the past because buildings were constructed in a manner to have a roof that could support the weight of the air material separator. Many newly-constructed manufacturing or processing facilities are single story structures having a relatively low, light-weight roof that typically cannot support the weight of an air material separator. The art thus desires an air material separator that can be placed inside buildings having low roofs and roofs that cannot support heavy equipment. Ideally, the air material separator must be light enough to be suspended from the roof joists.
A cyclone is an air material separator used in past separation applications. Cyclones are typically relatively tall so that the cyclonic action inside the cyclone has enough time to force the materials to the outside of the separator before the air flow is turned sharply upward to exit the device. The height of most cyclones prevent them from being used inside building structures. For example, one type of 9,000 CFM cyclone is about 210 inches tall (17xc2xd feet). An existing 14,500 CFM cyclone is about 254 inches tall (over 21 feet). An existing 21,500 CFM cyclone is about 303 inches tall (25 feet tall).
Other types of air material separators known in the art function by slowing the scrap-laden airflow to a velocity slow enough to cause the scrap to fall out of the airflow. These devices may also redirect the flow as it is being slowed to encourage the scrap to fall out of the flow. These types of devices typically use an expansion chamber to slow the velocity of the flow.
The invention provides an air material separator that may be used to separate scrap from a conveying airflow while having a relatively low weight and short height so that the separator may be positioned within today""s single-story manufacturing or processing facilities. The air material separator of the invention includes a generally cylindrical inlet chamber having a spiral wall that directs the inlet flow circumferentially and downwardly. An outlet chamber is positioned below the inlet chamber and includes a conical, perforated wall that allows the conveying air flow to escape through the perforated wall. The scrap carried by the conveying air flow cannot pass through the perforated wall and moves down and out an outlet at the bottom of the conical wall. The overall height of the device is substantially less than prior art air material separators.
In one embodiment of the invention, a shroud may be positioned about the conical wall to control the removal of the air flow from the air material separator to contain any expelled particles or dust.
Another objective of the invention is to provide an air material separator wherein the air does not have to be slowed to a low velocity to separate the scrap from the air.